Micro-blogging site Twitter has reportedly just passed the milestone of 300 million accounts, but only around a sixth are actually considered 'active'.

According to Twitter-tracking website Twopcharts, the website now has around 301,000,000 users and is adding new members at rate of 8.8 per second.

However, the Business Insider puts the actual number of 'active' Twitter accounts, constituting those users that follow eight or more other accounts, at between 50m and 60m. Counting only accounts that follow 32 or more users, and that number falls to around 21m active members.